World Table Tennis
AbbreviationWTT
Formation2019 (age 7)
Websiteworldtabletennis.com

World Table Tennis, stylized as WTT, is an organization created by the ITTF in 2019 that runs commercialized table tennis tournaments.[1] Its inaugural tournament was held in November 2020 in Macao. It is distinguished from the predecessor ITTF World Tour by various rules changes and big prize money for commercialized purposes.[2][3][4] The head of its council is Liu Guoliang, a former Olympic gold medalist and former head coach of China.[2] The WTT is headquartered in Singapore, with other offices in China, Europe, and the US.

Background

In 1926, the ITTF was founded by William Henry Lawes of Wymondham and Ivor Montagu[5]. The nine founding members were Austria, Czechoslovakia, Denmark, England, Germany, Hungary, India, Sweden and Wales. The first international tournament was held in January 1926 in Berlin, and the first World Table Tennis Championships was held in December 1926 in London.[6] It was the only event for over 50 years that was run and managed commercially by the ITTF.

In 1980, the ITTF World Cups was introduced, followed by the ITTF World Tour in 1996. Until 2003, commercial rights for these events were passed on to the local organising committees (LOC) but a different approach was taken to centralise rights through the creation of TMS.[clarification needed] TMS was tasked to manage these rights on behalf of ITTF, until 2017 when ITTF decided to buy back the rights to be taken in house.[7]

In 2018, professional consultants Deloitte and Withers were engaged to assist with remodelling the way that the ITTF does business.[8] Through full models and financial understanding of our events and other worldwide properties, ITTF sought to understand the untapped commercial potential of table tennis. One key finding led to the idea of separation between the management of the professional and institutional structures of table tennis.

On 30 May 2019, ITTF announced the idea of World Table Tennis (WTT),[9] a new commercial vehicle for table tennis. To launch WTT, the ITTF executive committee appointed a selection panel. The panel included ITTF President Thomas Weikert, ITTF Deputy President Khalil Al-Mohannadi, ITTF Executive Vice President for Finance Petra Sorling, ITTF CEO Steve Dainton, and ITTF Marketing Director Matthew Pound.[8][10]

Recent hires

WTT also announced the hire of Philippe Le Floc’h, former Chief Commercial Officer at FIFA and marketing director at UEFA, as Senior Commercial Strategy Consultant, in line with WTT's aim to commercialise the sport.[11][10] Shortly afterwards, Stephen Duckitt, who had 15 years of sports management experience, primarily with WTA and ATP, was announced as WTT Event Strategy Director.[8]

On 29 June 2020, WTT announced that China Table Tennis Association President, Liu Guoliang had accepted the role as Chair of the WTT Council. The WTT Council is tasked to ensure the healthy development of WTT and to be at the helm of the future development of table tennis.[12][13] WTT Macao was announced on 11 September 2020 to be held between 25 and 29 November 2020.[14] The debut event was a promotional showcase featuring 16 of the world's best male and 16 of the world's best female players. The event implemented a brand new format with innovative scoring methods. It also featured a prize purse of US$800,000 with players paid a minimum of US$15,000, and earning more prize money per match they win.[15][16]

Next to join was Melissa Soobratty. Announced on 4 December 2020, the former vice president, Media at Football Marketing Asia joined as WTT Senior Media Director to oversee all areas related to content, to further professionalise the organisation's expanding media operations.[17]

WTT event structure

Tournaments2019−present
TiersIGrand Smash
IIWTT SeriesWTT Finals
(WTT Cup Finals)
IIIWTT Champions
(WTT Champion Series)
IVWTT Contender
Series
WTT Star Contenders
VWTT Contenders

Grand Smash

The Grand Smashes will become the pillars of the sport and the most important events in the table tennis calendar. The events will feature both Men's and Women's singles draws with more players now receiving automatic entry into events. There will be fewer seeded players and a separate qualifying draw to ensure that the excitement kicks off right from the start. Doubles and Mixed Doubles events will also be played during the Grand Smashes.[18][19]

Dates: Fixed dates on the annual WTT Calendar

Players: 64 Men's & Women's Singles, Doubles & Mixed doubles draw

Length of event: 10 Days + Qualification

Prize Pool: Up to US$3 million

Number of events: Up to 4

Singapore Smash
YearMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2022Fan Zhendong (2)Chen MengFan Zhendong (2)
Wang Chuqin (2)
Wang Manyu (2)
Sun Yingsha (2)
Wang Chuqin (3)
Sun Yingsha (3)
2023Sun Yingsha
2024Wang ChuqinWang ManyuMa Long
Lin Gaoyuan
Chen Meng
Wang Manyu (3)
2025Lin ShidongSun Yingsha (2)Wang Chuqin (3)
Lin Shidong
Wang Manyu (4)
Kuai Man
Lin Shidong
Kuai Man
2026Wang Chuqin (2)Sun Yingsha (3)Félix Lebrun
Alexis Lebrun
Miwa Harimoto
Hina Hayata
Hugo Calderano
Bruna Takahashi
Saudi Smash
YearMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2024Wang ChuqinChen MengMa Long
Wang Chuqin
Chen Meng
Wang Manyu
Wang Chuqin
Sun Yingsha
China Smash
YearMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2024Lin ShidongSun YingshaLiang Jingkun
Wang Chuqin
Qian Tianyi
Chen Xingtong
Lin Shidong
Kuai Man
2025Wang ChuqinWang ManyuWang Chuqin (2)
Lin Shidong
Wang Manyu
Kuai Man
Wang Chuqin
Sun Yingsha
2026
United States Smash
YearMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2025Wang ChuqinZhu YulingLim Jong-hoon
An Jae-hyun
Wang Yidi
Kuai Man
Lin Shidong
Kuai Man
2026
Europe Smash - Sweden
YearMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2025Truls MöregårdhSun YingshaWong Chun Ting
Baldwin Chan
Wang Manyu
Sun Yingsha
Lin Shidong
Kuai Man
2026

WTT Series

The WTT Series serves as the primary platform for professional table tennis players to compete at the international level. It is divided into three tiers — Cup Finals, Champion Series, and Contender Series — to provide athletes with sufficient competitive opportunities. WTT also focuses on hosting events in distinctive venues worldwide, such as theatres, bars, clubs, and stadiums, aiming to create engaging and intimate experiences that bring fans closer to the athletes.[19][20]

WTT Finals

The WTT Finals are split into Men's and Women's events that will be held separately. The top 16 players of the year will qualify for this year-end event together with the best 8 pairs. Qualification will be determined by the player's performance throughout the WTT season and reflected through their Table Tennis World Ranking.

The first two editions of WTT Finals (2021 and 2022) was known as WTT Cup Finals. WTT stated that the winners of the WTT Cup Finals would win the prestigious ITTF World Cup trophies in March 2021, but the winners have been actually presented with WTT Finals specific trophies since the inaugural edition.

Players: 16 in Men's & Women's Singles, Top 8 pair in doubles

Length of event: 5 days

Prize Pool: Up to US$1.5million each

Number of events: 2

YearHost cityMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2021SingaporeFan ZhendongSun YingshaN/AN/AN/A
2022Xinxiang, ChinaWang Chuqin
2023Doha, Qatar (men)
Nagoya, Japan (women)
Xiang Peng
Yuan Licen
Wang Manyu
Sun Yingsha
2024Fukuoka, JapanWang ManyuAlexis Lebrun
Félix Lebrun
Honoka Hashimoto
Hitomi Sato
2025Hong Kong, ChinaTomokazu HarimotoN/AN/ALim Jong-hoon
Shin Yu-bin
2026Hong Kong, China


WTT Champions

The WTT Champion Series is exclusive to the top 32 men and women in the world. Four separate men's and women's event will be held with up to US$5million up for grabs. The matches will be played on one table to ensure that the best TV production and best entertainment is presented to fans.

Players: 32 Men's & Women's Singles

Length of event: 6 days

Prize Pool: Up to US$5million

Number of events: 4 men & 4 women

TourHost cityMen's singlesWomen's singles
2022
WTT Champions European Summer SeriesBudapest, HungaryTomokazu HarimotoWang Manyu
WTT Champions MacaoMacauWang ChuqinSun Yingsha
2023
WTT Champions XinxiangXinxiang, ChinaFan ZhendongSun Yingsha
WTT Champions MacaoMacauWang ChuqinWang Manyu
WTT Champions FrankfurtFrankfurt, GermanyLin Yun-juWang Yidi
2024
WTT Champions IncheonIncheon, South KoreaLiang JingkunSun Yingsha
WTT Champions ChongqingChongqing, ChinaFan Zhendong
WTT Champions MacaoMacauLin Shidong
WTT Champions MontpellierMontpellier, FranceFélix LebrunSatsuki Odo
WTT Champions FrankfurtFrankfurt, GermanyLin ShidongWang Manyu
2025
WTT Champions ChongqingChongqing, ChinaWang ChuqinSun Yingsha
WTT Champions IncheonIncheon, South KoreaXiang PengWang Yidi
WTT Champions YokohamaYokohama, JapanTomokazu HarimotoChen Xingtong
WTT Champions MacaoMacauWang ChuqinSun Yingsha
WTT Champions MontpellierMontpellier, FranceTruls MöregårdhWang Yidi
WTT Champions FrankfurtFrankfurt, GermanySora MatsushimaHina Hayata
2026
WTT Champions DohaDoha, QatarLin Yun-juZhu Yuling
WTT Champions ChongqingChongqing, ChinaFélix LebrunMiwa Harimoto
WTT Champions YokohamaYokohama, Japan
WTT Champions MacaoMacau
WTT Champions MontpellierMontpellier, France
WTT Champions GermanyTBC, Germany

WTT Star Contenders

WTT Star Contenders will consist of 6 events throughout the year featuring 48 men and 48 women. These events will serve as the platform for the next best in the world to earn ranking points to make the step up into the WTT Champions Series.

Players: 48 Men's & Women's Singles

Length of event: 6 days + Qualification

Number of events: 6

TourHost cityMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2021
WTT Star Contender Doha IDoha,
Qatar
Tomokazu HarimotoMima ItoLee Sang-su
Jeoung Young-sik
Shin Yu-bin
Jeon Ji-hee
Cheng I-ching
Lin Yun-ju
WTT Star Contender Doha IIDoha,
Qatar
Hugo CalderanoHina HayataAn Jae-hyun
Cho Seung-min
Miyu Nagasaki
Minami Ando
Shunsuke Togami
Hina Hayata
2022
WTT Star Contender DohaDoha,
Qatar
Andrej GacinaMiyuu KiharaBenedikt Duda
Dang Qiu
Miyuu Kihara
Miyu Nagasaki
Emmanuel Lebesson
Jia Nan Yuan
WTT Star Contender European Summer SeriesBudapest,
Hungary
Wang ChuqinWang YidiCho Dae-seong
Lee Sang-su
Sun Yingsha
Wang Manyu
Wang Chuqin
Wang Manyu
2023
WTT Star Contender GoaGoa,
India
Liang JingkunWang YidiAn Jae-hyun
Cho Seung-min
Miyu Nagasaki
Miwa Harimoto
Jang Woo-jin
Jeon Ji-hee
WTT Star Contender BangkokBangkok,
Thailand
Lin GaoyuanChen XingtongLin Gaoyuan
Lin Shidong
Chen Xingtong
Kuai Man
Lin Gaoyuan
Chen Xingtong
WTT Star Contender LjubljanaLjubljana,
Slovenia
Fan ZhendongSun YingshaLin Shidong
Xiang Peng
Wang Yidi
Kuai Man
Wang Chuqin
Sun Yingsha
WTT Star Contender LanzhouLanzhou,
China
Wang ChuqinAlexis Lebrun
Félix Lebrun
Chen Meng
Wang Manyu
Lin Shidong
Kuai Man
2024
WTT Star Contender DohaDoha,
Qatar
Wang ChuqinSun YingshaLiang Jingkun
Yuan Licen
Chen Xingtong
Qian Tianyi
Wang Chuqin
Sun Yingsha
WTT Star Contender GoaGoa,
India
Félix LebrunCheng I-chingLim Jong-hoon
An Jae-hyun
Shin Yu-bin
Jeon Ji-hee
Lim Jong-hoon
Shin Yu-bin
WTT Star Contender LjubljanaLjubljana,
Slovenia
Hugo CalderanoHina HayataAnton Källberg
Kristian Karlsson
Miyuu Kihara
Miyu Nagasaki
Tomokazu Harimoto
Hina Hayata
WTT Star Contender BangkokBangkok,
Thailand
Tomokazu HarimotoMima ItoTomokazu Harimoto
Sora Matsushima
Honoka Hashimoto
Hitomi Sato
2025
WTT Star Contender DohaDoha,
Qatar
Tomokazu HarimotoKuai ManXu Yingbin
Xiang Peng
Satsuki Odo
Sakura Yokoi
Sora Matsushima
Miwa Harimoto
WTT Star Contender ChennaiChennai,
India
Oh Jun-sungMiwa HarimotoLim Jong-hoon
An Jae-hyun
Miwa Harimoto
Miyuu Kihara
Lim Jong-hoon
Shin Yu-bin
WTT Star Contender LjubljanaLjubljana,
Slovenia
Hugo CalderanoMiyu NagasakiMiwa Harimoto
Satsuki Odo
WTT Star Contender Foz do IguaçuFoz do Iguaçu,
Brazil
Miwa HarimotoBenedikt Duda
Dang Qiu
Satoshi Aida
Honoka Hashimoto
WTT Star Contender LondonLondon,
United Kingdom
Dang QiuKuo Guan-Hong
Feng Yi-Hsin
Shi Xunyao
Zhang Xiangyu
Lin Yun-Ju
Cheng I-Ching
WTT Star Contender MuscatMuscat,
Oman
Felix LebrunMiyuu KiharaLim Jong-hoon
Oh Jun-sung
Satsuki Odo
Sakura Yokoi
Satoshi Aida
Hitomi Sato
2026
WTT Star Contender DohaDoha,
Qatar
Zhou QihaoZhu YulingCho Dae-seong
Jang Woo-jin
Satsuki Odo
Sakura Yokoi
Wong Chun-ting
Doo Hoi Kem
WTT Star Contender ChennaiChennai,
India
Lubomír JančaříkSatsuki OdoFlavien Coton
Thibault Poret
Sakura Yokoi
Sachi Aoki
Eduard Ionescu
Bernadette Szőcs

WTT Contenders

Then the final tier, the WTT Contenders, allows the rest of the professional players throughout the world rankings to develop their talents in up to 14 events per year, each one lasting for four days.

Players: Flexible playing system

Length of event: Flexible playing system

Number of events: Up to 14 events

TourHost cityMen's singlesWomen's singlesMen's doublesWomen's doublesMixed doubles
2023
WTT Contender DurbanDurban,
South Africa
Hugo CalderanoQian TianyiChen Yuanyu
Lin Shidong
Zhang Rui
Kuai Man
Lin Shidong
Kuai Man
WTT Contender DohaDoha,
Qatar
Fan SiqiYu Ziyang
Zhou Kai
WTT Contender AmmanAmman,
Jordan
Lin ShidongMima ItoLiu Yebo
Xu Yingbin
Cheng I-ching
Li Yu-jhun
WTT Contender LagosLagos,
Nigeria
Zhou QihaoShin Yu-binJang Woo-jin
Lim Jong-hoon
Jeon Ji-hee
Shin Yu-bin
Xiang Peng
Liu Weishan
WTT Contender TunisTunis,
Tunisia
Anton KallbergMiwa HarimotoJang Woo-jin
Park Gang-hyeon
Sutirtha Mukherjee
Ayhika Mukherjee
Lin Yun-ju
Chen Szu-yu
WTT Contender ZagrebZagreb,
Croatia
Lin GaoyuanMiu HiranoLin Shidong
Yuan Licen
Jeon Ji-hee
Shin Yu-bin
Wang Chuqin
Sun Yingsha
WTT Contender LimaLima,
Peru
Marcos FreitasShin Yu-binMizuki Oikawa
Sora Matsushima
Álvaro Robles
María Xiao
WTT Contender Rio de JaneiroRio,
Brazil
Mattias FalckHina HayataAn Jae-hyun
Lim Jong-hoon
Lim Jong-hoon
Shin Yu-bin
WTT Contender AlmatyAlmaty,
Kazakhstan
Lin Yun-juKuai ManLin Shidong
Xu Yingbin
Chen Yi
Kuai Man
Cho Dae-seong
Joo Cheon-hui
WTT Contender MuscatMuscat,
Oman
Hugo CalderanoHina HayataPatrick Franziska
Dimitrij Ovtcharov
Ng Wing Lam
Zhu Chengzhu
Lin Yun-ju
Chen Szu-yu
WTT Contender AntalyaAntalya,
Turkey
Félix LebrunLim Jong-hoon
An Jae-hyun
Orawan Paranang
Suthasini Sawettabut
Tomokazu Harimoto
Hina Hayata
WTT Contender TaiyuanTaiyuan,
China
Liang JingkunWang ManyuLin Gaoyuan
Lin Shidong
Chen Xingtong
Qian Tianyi
Lin Shidong
Kuai Man
2024
WTT Contender DohaDoha,
Qatar
Timo BollJeon Ji-heeLim Jong-hoon
Lee Sang-su
Jeon Ji-hee
Shin Yu-bin
Wang Chuqin
Sun Yingsha
WTT Contender TaiyuanTaiyuan,
China
Liang JingkunChen XingtongMa Long
Lin Gaoyuan
Chen Yi
Kuai Man
Lin Shidong
Kuai Man
WTT Contender Rio de JaneiroRio,
Brazil
Hugo CalderanoMiyu NagasakiAn Jae-hyun
Oh Jun-sung
Honoka Hashimoto
Hitomi Sato
Lim Jong-hoon
Shin Yu-bin
WTT Contender MendozaMendoza,
Argentina
Benedikt DudaSakura MoriHoracio Cifuentes
Santiago Lorenzo
Sakura Mori
Miyu Nagasaki
Yuta Tanaka
Miyu Nagasaki
WTT Contender ZagrebZagreb,
Croatia
Alexis LebrunHina HayataAlexis Lebrun
Simon Gauzy
Sakura Yokoi
Satsuki Odo
Tomokazu Harimoto
Hina Hayata
WTT Contender LagosLagos,
Nigeria
Dimitrij OvtcharovSreeja AkulaHarmeet Desai
Manav Thakkar
Sreeja Akula
Archana Kamath
Lim Jong-hoon
Shin Yu-bin
WTT Contender TunisTunis,
Tunisia
Tomokazu HarimotoMiwa HarimotoSora Matsushima
Tomokazu Harimoto
Satsuki Odo
Sakura Yokoi
Tomokazu Harimoto
Hina Hayata
WTT Contender LimaLima,
Peru
Darko JorgicSatsuki OdoFlorian Bourrassaud
Esteban Dorr
Henrique Noguti
Giulia Takahashi
WTT Contender AlmatyAlmaty,
Kazakhstan
Lin ShidongShi XunyaoLin Shidong
Xu Yinbing
He Zhuojia
Liu Weishan
Lin Shidong
Kuai Man
WTT Contender MuscatMuscat,
Oman
Kuai ManYuan Licen
Xiang Peng
Yang Yiyun
Zhu Sibing
2025
WTT Contender MuscatMuscat,
Oman
Chen YuanyuShi XunyaoTomokazu Harimoto
Sora Matsushima
Satsuki Odo
Sakura Yokoi
Álvaro Robles
Maria Xiao
WTT Contender TaiyuanTaiyuan,
China
Sora MatsushimaHonoka HashimotoXu Yingbin
Xiang Peng
Kim Na-yeong
Ryu Han-na
Lim Jong-hoon
Kim Na-yeong
WTT Contender TunisTunis,
Tunisia
Félix LebrunMiwa HarimotoBenedikt Duda
Andre Bertelsmeier
Miwa Harimoto
Miyuu Kihara
Manush Shah
Diya Chitale
WTT Contender SkopjeSkopje,
North Macedonia
Benedikt DudaJia Nan YuanLim Jong-hoon
Oh Jun-sung
Kim Na-yeong
Ryu Han-na
Kristian Karlsson
Christina Kallberg
WTT Contender ZagrebZagreb,
Croatia
Tomokazu HarimotoSatsuki OdoWong Chun Ting
Chan Baldwin
Miwa Harimoto
Satsuki Odo
Lim Jong-hoon
Shin Yu-bin
WTT Contender LagosLagos,
Nigeria
Anders LindHonoka HashimotoSathiyan Gnanasekaran
Akash Pal
Kim Na-yeong
Ryu Han-na
Jules Rolland
Prithika Pavade
WTT Contender Buenos AiresBuenos Aires,
Argentina
Hugo CalderanoMiwa HarimotoKazuki Hamada
Hiromu Kobayashi
Miwa Harimoto
Satsuki Odo
Hugo Calderano
Bruna Takahashi
WTT Contender AlmatyAlmaty,
Kazakhstan
Shunsuke TogamiHonoka HashimotoYuan Lichen
Xu Yingbin
Honoka Hashimoto
Hitomi Sato
Huang Youzheng
Shi Xunyao
2026
WTT Contender MuscatMuscat,
Oman
Wen RuiboShi XunyaoHuang Youzheng
Lin Shidong
Qin Yuxuan
Zong Geman
Manush Shah
Diya Chitale
WTT Contender TunisTunis,
Tunisia
Flavien CotonElizabet AbraamianFlorian Bourrassaud
Esteban Dorr
Elizabet Abraamian
Maria Panfilova
Álvaro Robles
María Xiao
WTT Contender TaiyuanTaiyuan,
China
Wen RuiboSatsuki OdoWen Ruibo
Li Hechen
Shi Xunyao
Han Feier
Huang Youzheng
Shi Xunyao
WTT Contender LagosLagos,
Nigeria
Anders LindManav Thakkar
Manush Shah
Reina Aso
Joo Cheon-hui
Manush Shah
Diya Chitale
WTT Contender SkopjeSkopje,
North Macedonia

See also

References

  1. ^ "Introducing WTT". Worldtabletennis.com
  2. ^ "Table tennis requires change and innovation, says WTT Council Chair Liu". China Daily. 2020-12-01.
  3. ^ Hopkins, Steve (2020-11-30). "WTT Macau Recap: Raising the $ Bar for the Sport". ButterflyOnline.com
  4. ^ "Frequently Asked Question". WTT. 2020-06-11. Archived 2020-12-04 at the Wayback Machine.
  5. ^ "About us - International Table Tennis Federation". International Table Tennis Federation. Archived 2024-07-16 at the Wayback Machine. Retrieved 2026-02-09.
  6. ^ "ITTF Archives". Archived 2011-03-01 at the Wayback Machine.
  7. ^ "ITTF and TMS International end exclusive marketing agreement". ittf.com. 22 November 2016. Retrieved 3 April 2024.
  8. ^ "A Message from the CEO I World Table Tennis Origins". Around The Rings
  9. ^ "ITTF ready for revolution through World Table Tennis". ITTF.com. 29 May 2019.
  10. ^ Carp, Sam (3 March 2020). "World Table Tennis plans include event revamp and double prize money". Sports Pro Media
  11. ^ "Welcome to World Table Tennis!". www.gosports.com.my
  12. ^ "China's table tennis chief Liu Guoliang named WTT Council head". Chinadaily. 29 June 2020.
  13. ^ McCullagh, Kevin (29 June 2020). "Chinese table tennis president appointed to lead WTT Council". Sport business
  14. ^ Hua, Xia (12 November 2020). "WTT tournament to debut in Macao in November". Xinhua Net
  15. ^ "Table tennis' biggest stars to compete at WTT Macao 2020 presented by Galaxy Entertainment Group". Government Information Bureau of the Macao SAR. 19 November 2020.
  16. ^ Hopkins, Steve (30 November 2020). "WTT Macau Recap: Raising the $ Bar for the Sport". Butterfly Online
  17. ^ Cline, Warren. "Melissa Soobratty joins as WTT Senior Media Director". thesportyworld.com. Retrieved 5 December 2020.; Svenson, David (4 December 2020). "WTT appoints Soobratty to lead media rights strategy". Sports Business
  18. ^ "Grand Smashes – everything you need to know!". Worldtabletennis.com
  19. ^ Lee, David (4 March 2020). "Paddlers get bigger payout in new WTT format". Straits Times
  20. ^ Houston, Michael (13 March 2020). "Bidding open for 2021 rebranded World Table Tennis events". www.insidethegames.biz